CVE-2016-9243: PYSEC-2017-8 - HKDF in cryptography before 1.5.2 returns an empty byte-string if used with a length less than algorithm.digest_size.

CVE-2016-9243 · Severity: low · CVSS 3 · Published 2017-03-27

HKDF in cryptography before 1.5.2 returns an empty byte-string if used with a length less than algorithm.digest_size.

Technologies: cryptography (PyPI). Vendors: PyPI.

Quick answers

Is CVE-2016-9243 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2016-9243 being exploited in the wild.
How severe is CVE-2016-9243?
Low severity, with a CVSS score of 3, published 27 March 2017.
Which products and versions are affected?
cryptography (PyPI) ECOSYSTEM:introduced=0,fixed=1.5.3, GIT:introduced=0,fixed=b924696b2e8731f39696584d12cceeb3aeb2d874|ECOSYSTEM:introduced=0,fixed=1.5.3.
Is there a fix for CVE-2016-9243?
Yes. cryptography (PyPI): upgrade to 1.5.3 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
Am I affected by CVE-2016-9243?
Check whether you run cryptography (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • cryptography (PyPI): upgrade to 1.5.3 or later
    pip install "cryptography>=1.5.3"

Affected products

  • cryptography (PyPI) ECOSYSTEM:introduced=0,fixed=1.5.3, GIT:introduced=0,fixed=b924696b2e8731f39696584d12cceeb3aeb2d874|ECOSYSTEM:introduced=0,fixed=1.5.3

Identifiers

  • CVE-2016-9243
  • GHSA-q3cj-2r34-2cwc
  • PYSEC-2017-8

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